container_bloomfilter.c

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/*
     This file is part of GNUnet.
     Copyright (C) 2001, 2002, 2003, 2004, 2006, 2008, 2011, 2012, 2018 GNUnet e.V.
 
     GNUnet is free software: you can redistribute it and/or modify it
     under the terms of the GNU Affero General Public License as published
     by the Free Software Foundation, either version 3 of the License,
     or (at your option) any later version.
 
     GNUnet is distributed in the hope that it will be useful, but
     WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     Affero General Public License for more details.
 
     You should have received a copy of the GNU Affero General Public License
     along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
     SPDX-License-Identifier: AGPL3.0-or-later
 */
#include "platform.h"
#include "gnunet_util_lib.h"
 
#define LOG(kind, ...) \
  GNUNET_log_from (kind, "util-container-bloomfilter", __VA_ARGS__)
 
#define LOG_STRERROR(kind, syscall) \
  GNUNET_log_from_strerror (kind, "util-container-bloomfilter", syscall)
 
#define LOG_STRERROR_FILE(kind, syscall, filename)             \
  GNUNET_log_from_strerror_file (kind,                         \
                                 "util-container-bloomfilter", \
                                 syscall,                      \
                                 filename)
 
struct GNUNET_CONTAINER_BloomFilter
{
  char *bitArray;
 
  char *filename;
 
  struct GNUNET_DISK_FileHandle *fh;
 
  unsigned int addressesPerElement;
 
  size_t bitArraySize;
};
 
 
size_t
GNUNET_CONTAINER_bloomfilter_get_element_addresses (
  const struct GNUNET_CONTAINER_BloomFilter *bf)
{
  if (bf == NULL)
    return 0;
  return bf->addressesPerElement;
}
 
 
size_t
GNUNET_CONTAINER_bloomfilter_get_size (
  const struct GNUNET_CONTAINER_BloomFilter *bf)
{
  if (bf == NULL)
    return 0;
  return bf->bitArraySize;
}
 
 
struct GNUNET_CONTAINER_BloomFilter *
GNUNET_CONTAINER_bloomfilter_copy (
  const struct GNUNET_CONTAINER_BloomFilter *bf)
{
  return GNUNET_CONTAINER_bloomfilter_init (bf->bitArray,
                                            bf->bitArraySize,
                                            bf->addressesPerElement);
}
 
 
static void
setBit (char *bitArray,
        unsigned int bitIdx)
{
  size_t arraySlot;
  unsigned int targetBit;
 
  arraySlot = bitIdx / 8;
  targetBit = (1L << (bitIdx % 8));
  bitArray[arraySlot] |= targetBit;
}
 
 
static void
clearBit (char *bitArray, unsigned int bitIdx)
{
  size_t slot;
  unsigned int targetBit;
 
  slot = bitIdx / 8;
  targetBit = (1L << (bitIdx % 8));
  bitArray[slot] = bitArray[slot] & (~targetBit);
}
 
 
static bool
testBit (char *bitArray,
         unsigned int bitIdx)
{
  size_t slot;
  unsigned int targetBit;
 
  slot = bitIdx / 8;
  targetBit = (1L << (bitIdx % 8));
  if (bitArray[slot] & targetBit)
    return true;
  return false;
}
 
 
static void
incrementBit (char *bitArray,
              unsigned int bitIdx,
              const struct GNUNET_DISK_FileHandle *fh)
{
  off_t fileSlot;
  unsigned char value;
  unsigned int high;
  unsigned int low;
  unsigned int targetLoc;
 
  setBit (bitArray,
          bitIdx);
  if (GNUNET_DISK_handle_invalid (fh))
    return;
  /* Update the counter file on disk */
  fileSlot = bitIdx / 2;
  targetLoc = bitIdx % 2;
 
  GNUNET_assert (fileSlot ==
                 GNUNET_DISK_file_seek (fh, fileSlot, GNUNET_DISK_SEEK_SET));
  if (1 != GNUNET_DISK_file_read (fh, &value, 1))
    value = 0;
  low = value & 0xF;
  high = (value & (~0xF)) >> 4;
 
  if (targetLoc == 0)
  {
    if (low < 0xF)
      low++;
  }
  else
  {
    if (high < 0xF)
      high++;
  }
  value = ((high << 4) | low);
  GNUNET_assert (fileSlot ==
                 GNUNET_DISK_file_seek (fh, fileSlot, GNUNET_DISK_SEEK_SET));
  GNUNET_assert (1 == GNUNET_DISK_file_write (fh, &value, 1));
}
 
 
static void
decrementBit (char *bitArray,
              unsigned int bitIdx,
              const struct GNUNET_DISK_FileHandle *fh)
{
  off_t fileslot;
  unsigned char value;
  unsigned int high;
  unsigned int low;
  unsigned int targetLoc;
 
  if (GNUNET_DISK_handle_invalid (fh))
    return; /* cannot decrement! */
  /* Each char slot in the counter file holds two 4 bit counters */
  fileslot = bitIdx / 2;
  targetLoc = bitIdx % 2;
  if (GNUNET_SYSERR ==
      GNUNET_DISK_file_seek (fh, fileslot, GNUNET_DISK_SEEK_SET))
  {
    GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "seek");
    return;
  }
  if (1 != GNUNET_DISK_file_read (fh, &value, 1))
    value = 0;
  low = value & 0xF;
  high = (value & 0xF0) >> 4;
 
  /* decrement, but once we have reached the max, never go back! */
  if (targetLoc == 0)
  {
    if ((low > 0) && (low < 0xF))
      low--;
    if (low == 0)
    {
      clearBit (bitArray, bitIdx);
    }
  }
  else
  {
    if ((high > 0) && (high < 0xF))
      high--;
    if (high == 0)
    {
      clearBit (bitArray, bitIdx);
    }
  }
  value = ((high << 4) | low);
  if (GNUNET_SYSERR ==
      GNUNET_DISK_file_seek (fh, fileslot, GNUNET_DISK_SEEK_SET))
  {
    GNUNET_log_strerror (GNUNET_ERROR_TYPE_ERROR, "seek");
    return;
  }
  GNUNET_assert (1 == GNUNET_DISK_file_write (fh, &value, 1));
}
 
 
#define BUFFSIZE 65536
 
static enum GNUNET_GenericReturnValue
make_empty_file (const struct GNUNET_DISK_FileHandle *fh,
                 size_t size)
{
  char buffer[BUFFSIZE];
  size_t bytesleft = size;
  int res = 0;
 
  if (GNUNET_DISK_handle_invalid (fh))
    return GNUNET_SYSERR;
  memset (buffer, 0, sizeof(buffer));
  GNUNET_DISK_file_seek (fh, 0, GNUNET_DISK_SEEK_SET);
  while (bytesleft > 0)
  {
    if (bytesleft > sizeof(buffer))
    {
      res = GNUNET_DISK_file_write (fh, buffer, sizeof(buffer));
      if (res >= 0)
        bytesleft -= res;
    }
    else
    {
      res = GNUNET_DISK_file_write (fh, buffer, bytesleft);
      if (res >= 0)
        bytesleft -= res;
    }
    if (GNUNET_SYSERR == res)
      return GNUNET_SYSERR;
  }
  return GNUNET_OK;
}
 
 
/* ************** GNUNET_CONTAINER_BloomFilter iterator ********* */
 
typedef enum GNUNET_GenericReturnValue
(*BitIterator)(void *cls,
               const struct GNUNET_CONTAINER_BloomFilter *bf,
               unsigned int bit);
 
 
static void
iterateBits (const struct GNUNET_CONTAINER_BloomFilter *bf,
             BitIterator callback,
             void *arg,
             const struct GNUNET_HashCode *key)
{
  struct GNUNET_HashCode tmp = *key;
  int bitCount;
  unsigned int slot = 0;
 
  bitCount = bf->addressesPerElement;
  GNUNET_assert (bf->bitArraySize > 0);
  GNUNET_assert (bf->bitArraySize * 8LL > bf->bitArraySize);
  while (bitCount > 0)
  {
    while ( (0 != bitCount) &&
            (slot < (sizeof(struct GNUNET_HashCode) / sizeof(uint32_t))) )
    {
      if (GNUNET_YES !=
          callback (arg,
                    bf,
                    ntohl ((((uint32_t *) &tmp)[slot]))
                    % ((bf->bitArraySize * 8LL))))
        return;
      slot++;
      bitCount--;
    }
    if (0 == bitCount)
      break;
    GNUNET_CRYPTO_hash (&tmp,
                        sizeof(tmp),
                        &tmp);
    slot = 0;
  }
}
 
 
static enum GNUNET_GenericReturnValue
incrementBitCallback (void *cls,
                      const struct GNUNET_CONTAINER_BloomFilter *bf,
                      unsigned int bit)
{
  struct GNUNET_CONTAINER_BloomFilter *b = cls;
 
  incrementBit (b->bitArray,
                bit,
                bf->fh);
  return GNUNET_YES;
}
 
 
static enum GNUNET_GenericReturnValue
decrementBitCallback (void *cls,
                      const struct GNUNET_CONTAINER_BloomFilter *bf,
                      unsigned int bit)
{
  struct GNUNET_CONTAINER_BloomFilter *b = cls;
 
  decrementBit (b->bitArray,
                bit,
                bf->fh);
  return GNUNET_YES;
}
 
 
static enum GNUNET_GenericReturnValue
testBitCallback (void *cls,
                 const struct GNUNET_CONTAINER_BloomFilter *bf,
                 unsigned int bit)
{
  bool *arg = cls;
 
  if (! testBit (bf->bitArray, bit))
  {
    *arg = false;
    return GNUNET_NO;
  }
  return GNUNET_YES;
}
 
 
/* *********************** INTERFACE **************** */
 
struct GNUNET_CONTAINER_BloomFilter *
GNUNET_CONTAINER_bloomfilter_load (const char *filename,
                                   size_t size,
                                   unsigned int k)
{
  struct GNUNET_CONTAINER_BloomFilter *bf;
  char *rbuff;
  off_t pos;
  int i;
  size_t ui;
  off_t fsize;
  int must_read;
 
  GNUNET_assert (NULL != filename);
  if ((k == 0) || (size == 0))
    return NULL;
  if (size < BUFFSIZE)
    size = BUFFSIZE;
  ui = 1;
  while ((ui < size) && (ui * 2 > ui))
    ui *= 2;
  size = ui; /* make sure it's a power of 2 */
 
  bf = GNUNET_new (struct GNUNET_CONTAINER_BloomFilter);
  /* Try to open a bloomfilter file */
  if (GNUNET_YES == GNUNET_DISK_file_test (filename))
    bf->fh = GNUNET_DISK_file_open (filename,
                                    GNUNET_DISK_OPEN_READWRITE,
                                    GNUNET_DISK_PERM_USER_READ
                                    | GNUNET_DISK_PERM_USER_WRITE);
  if (NULL != bf->fh)
  {
    /* file existed, try to read it! */
    must_read = GNUNET_YES;
    if (GNUNET_OK !=
        GNUNET_DISK_file_handle_size (bf->fh,
                                      &fsize))
    {
      GNUNET_DISK_file_close (bf->fh);
      GNUNET_free (bf);
      return NULL;
    }
    if (0 == fsize)
    {
      /* found existing empty file, just overwrite */
      if (GNUNET_OK !=
          make_empty_file (bf->fh,
                           size * 4LL))
      {
        GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING,
                             "write");
        GNUNET_DISK_file_close (bf->fh);
        GNUNET_free (bf);
        return NULL;
      }
    }
    else if (fsize != ((off_t) size) * 4LL)
    {
      GNUNET_log (
        GNUNET_ERROR_TYPE_ERROR,
        _ (
          "Size of file on disk is incorrect for this Bloom filter (want %llu, have %llu)\n"),
        (unsigned long long) (size * 4LL),
        (unsigned long long) fsize);
      GNUNET_DISK_file_close (bf->fh);
      GNUNET_free (bf);
      return NULL;
    }
  }
  else
  {
    /* file did not exist, don't read, just create */
    must_read = GNUNET_NO;
    bf->fh = GNUNET_DISK_file_open (filename,
                                    GNUNET_DISK_OPEN_CREATE
                                    | GNUNET_DISK_OPEN_READWRITE,
                                    GNUNET_DISK_PERM_USER_READ
                                    | GNUNET_DISK_PERM_USER_WRITE);
    if (NULL == bf->fh)
    {
      GNUNET_free (bf);
      return NULL;
    }
    if (GNUNET_OK != make_empty_file (bf->fh, size * 4LL))
    {
      GNUNET_log_strerror (GNUNET_ERROR_TYPE_WARNING, "write");
      GNUNET_DISK_file_close (bf->fh);
      GNUNET_free (bf);
      return NULL;
    }
  }
  bf->filename = GNUNET_strdup (filename);
  /* Alloc block */
  bf->bitArray = GNUNET_malloc_large (size);
  if (NULL == bf->bitArray)
  {
    if (NULL != bf->fh)
      GNUNET_DISK_file_close (bf->fh);
    GNUNET_free (bf->filename);
    GNUNET_free (bf);
    return NULL;
  }
  bf->bitArraySize = size;
  bf->addressesPerElement = k;
  if (GNUNET_YES != must_read)
    return bf; /* already done! */
  /* Read from the file what bits we can */
  rbuff = GNUNET_malloc (BUFFSIZE);
  pos = 0;
  while (pos < ((off_t) size) * 8LL)
  {
    int res;
 
    res = GNUNET_DISK_file_read (bf->fh, rbuff, BUFFSIZE);
    if (res == -1)
    {
      LOG_STRERROR_FILE (GNUNET_ERROR_TYPE_WARNING, "read", bf->filename);
      GNUNET_free (rbuff);
      GNUNET_free (bf->filename);
      GNUNET_DISK_file_close (bf->fh);
      GNUNET_free (bf);
      return NULL;
    }
    if (res == 0)
      break;   /* is ok! we just did not use that many bits yet */
    for (i = 0; i < res; i++)
    {
      if ((rbuff[i] & 0x0F) != 0)
        setBit (bf->bitArray, pos + i * 2);
      if ((rbuff[i] & 0xF0) != 0)
        setBit (bf->bitArray, pos + i * 2 + 1);
    }
    if (res < BUFFSIZE)
      break;
    pos += BUFFSIZE * 2;   /* 2 bits per byte in the buffer */
  }
  GNUNET_free (rbuff);
  return bf;
}
 
 
struct GNUNET_CONTAINER_BloomFilter *
GNUNET_CONTAINER_bloomfilter_init (const char *data,
                                   size_t size,
                                   unsigned int k)
{
  struct GNUNET_CONTAINER_BloomFilter *bf;
 
  if ((0 == k) || (0 == size))
    return NULL;
  bf = GNUNET_new (struct GNUNET_CONTAINER_BloomFilter);
  bf->filename = NULL;
  bf->fh = NULL;
  bf->bitArray = GNUNET_malloc_large (size);
  if (NULL == bf->bitArray)
  {
    GNUNET_free (bf);
    return NULL;
  }
  bf->bitArraySize = size;
  bf->addressesPerElement = k;
  if (NULL != data)
    GNUNET_memcpy (bf->bitArray, data, size);
  return bf;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_CONTAINER_bloomfilter_get_raw_data (
  const struct GNUNET_CONTAINER_BloomFilter *bf,
  char *data,
  size_t size)
{
  if (NULL == bf)
    return GNUNET_SYSERR;
  if (bf->bitArraySize != size)
    return GNUNET_SYSERR;
  GNUNET_memcpy (data, bf->bitArray, size);
  return GNUNET_OK;
}
 
 
void
GNUNET_CONTAINER_bloomfilter_free (struct GNUNET_CONTAINER_BloomFilter *bf)
{
  if (NULL == bf)
    return;
  if (bf->fh != NULL)
    GNUNET_DISK_file_close (bf->fh);
  GNUNET_free (bf->filename);
  GNUNET_free (bf->bitArray);
  GNUNET_free (bf);
}
 
 
void
GNUNET_CONTAINER_bloomfilter_clear (struct GNUNET_CONTAINER_BloomFilter *bf)
{
  if (NULL == bf)
    return;
 
  memset (bf->bitArray, 0, bf->bitArraySize);
  if (bf->filename != NULL)
    make_empty_file (bf->fh, bf->bitArraySize * 4LL);
}
 
 
bool
GNUNET_CONTAINER_bloomfilter_test (
  const struct GNUNET_CONTAINER_BloomFilter *bf,
  const struct GNUNET_HashCode *e)
{
  bool res;
 
  if (NULL == bf)
    return true;
  res = true;
  iterateBits (bf,
               &testBitCallback,
               &res,
               e);
  return res;
}
 
 
void
GNUNET_CONTAINER_bloomfilter_add (struct GNUNET_CONTAINER_BloomFilter *bf,
                                  const struct GNUNET_HashCode *e)
{
  if (NULL == bf)
    return;
  iterateBits (bf,
               &incrementBitCallback,
               bf,
               e);
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_CONTAINER_bloomfilter_or (struct GNUNET_CONTAINER_BloomFilter *bf,
                                 const char *data,
                                 size_t size)
{
  unsigned int i;
  unsigned int n;
  unsigned long long *fc;
  const unsigned long long *dc;
 
  if (NULL == bf)
    return GNUNET_YES;
  if (bf->bitArraySize != size)
    return GNUNET_SYSERR;
  fc = (unsigned long long *) bf->bitArray;
  dc = (const unsigned long long *) data;
  n = size / sizeof(unsigned long long);
 
  for (i = 0; i < n; i++)
    fc[i] |= dc[i];
  for (i = n * sizeof(unsigned long long); i < size; i++)
    bf->bitArray[i] |= data[i];
  return GNUNET_OK;
}
 
 
enum GNUNET_GenericReturnValue
GNUNET_CONTAINER_bloomfilter_or2 (
  struct GNUNET_CONTAINER_BloomFilter *bf,
  const struct GNUNET_CONTAINER_BloomFilter *to_or)
{
  unsigned int i;
  unsigned int n;
  unsigned long long *fc;
  const unsigned long long *dc;
  size_t size;
 
  if (NULL == bf)
    return GNUNET_OK;
  if (bf->bitArraySize != to_or->bitArraySize)
  {
    GNUNET_break (0);
    return GNUNET_SYSERR;
  }
  size = bf->bitArraySize;
  fc = (unsigned long long *) bf->bitArray;
  dc = (const unsigned long long *) to_or->bitArray;
  n = size / sizeof(unsigned long long);
 
  for (i = 0; i < n; i++)
    fc[i] |= dc[i];
  for (i = n * sizeof(unsigned long long); i < size; i++)
    bf->bitArray[i] |= to_or->bitArray[i];
  return GNUNET_OK;
}
 
 
void
GNUNET_CONTAINER_bloomfilter_remove (struct GNUNET_CONTAINER_BloomFilter *bf,
                                     const struct GNUNET_HashCode *e)
{
  if (NULL == bf)
    return;
  if (NULL == bf->filename)
    return;
  iterateBits (bf,
               &decrementBitCallback,
               bf,
               e);
}
 
 
void
GNUNET_CONTAINER_bloomfilter_resize (struct GNUNET_CONTAINER_BloomFilter *bf,
                                     GNUNET_CONTAINER_HashCodeIterator iterator,
                                     void *iterator_cls,
                                     size_t size,
                                     unsigned int k)
{
  struct GNUNET_HashCode hc;
  unsigned int i;
 
  GNUNET_free (bf->bitArray);
  i = 1;
  while (i < size)
    i *= 2;
  size = i; /* make sure it's a power of 2 */
  bf->addressesPerElement = k;
  bf->bitArraySize = size;
  bf->bitArray = GNUNET_malloc (size);
  if (NULL != bf->filename)
    make_empty_file (bf->fh, bf->bitArraySize * 4LL);
  while (GNUNET_YES == iterator (iterator_cls, &hc))
    GNUNET_CONTAINER_bloomfilter_add (bf, &hc);
}
 
 
/* end of container_bloomfilter.c */